This invention relates to a brake release mechanism for manually releasing the brake of a hydraulic motor for a hydrostatic transmission arranged to be actuated by the force of a spring and released by a fluid pressure applied thereon.
The brake for hydraulic motor of the kind specified is arranged to be actuated automatically when the supply of fluid pressure is interrupted by stopping an engine.
Under such a condition, however, the vehicle body cannot be towed, and therefore it is required to operate a brake release mechanism separately so as to release the brake.
A conventional brake release mechanism is disclosed, for example, in U.S. Pat. No. 4,195,716.
The above-mentioned prior art brake release mechanism is arranged to supply the fluid pressure into the cylinder of the brake by means of a manual pump to thereby release the brake and is also arranged, when actuating the brake again, to open a drain valve installed in the fluid conduit connected between the manual pump and the brake cylinder so as to drain the fluid pressure thereby actuating the brake.
For this reason, in the case the above-mentioned brake release mechanism is employed, it is necessary for the operator to select either of brake releasing condition or brake actuated condition, and therefore it is impossible to control the braking operation delicately when the vehicle is being towed.